U.S. patent application number 12/702308 was filed with the patent office on 2010-06-10 for increasing surface active properties of surfactants.
This patent application is currently assigned to Advanced BioCatalytics Corporation. Invention is credited to John W. Baldridge, Carl W. Podella.
Application Number | 20100144583 12/702308 |
Document ID | / |
Family ID | 35187858 |
Filed Date | 2010-06-10 |
United States Patent
Application |
20100144583 |
Kind Code |
A1 |
Baldridge; John W. ; et
al. |
June 10, 2010 |
INCREASING SURFACE ACTIVE PROPERTIES OF SURFACTANTS
Abstract
Surfactant-containing compositions are described which include a
protein component that has the effect of improving the
surface-active properties of the surfactants contained in the
compositions. The surfactant-containing compositions having the
protein component demonstrate significantly lower critical micelle
concentrations (CMC) than do comparable compositions having no
protein component. In addition, the surfactant-containing
compositions having the protein component has the effect of
converting greasy waste contaminants to surface active
materials.
Inventors: |
Baldridge; John W.; (Newport
Beach, CA) ; Podella; Carl W.; (Irvine, CA) |
Correspondence
Address: |
TechLaw LLP
10755 Scripps Poway Parkway, Suite 465
San Diego
CA
92131
US
|
Assignee: |
Advanced BioCatalytics
Corporation
Irvine
CA
|
Family ID: |
35187858 |
Appl. No.: |
12/702308 |
Filed: |
February 9, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10837312 |
Apr 29, 2004 |
7659237 |
|
|
12702308 |
|
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Current U.S.
Class: |
510/434 |
Current CPC
Class: |
C11D 1/123 20130101;
C11D 3/381 20130101; C11D 3/384 20130101; C11D 3/38 20130101 |
Class at
Publication: |
510/434 |
International
Class: |
C11D 3/26 20060101
C11D003/26 |
Claims
1. A method of making a liquid detergent, comprising: providing a
detersive surfactant package of one or more surfactants; providing
at least one adjunct detergent ingredient, providing a protein
component comprising a mixture of multiple intracellular proteins,
at least a portion of the mixture including yeast polypeptides
obtained from fermenting yeast cells and yeast heat shock proteins
resulting from subjecting a mixture obtained from the yeast
fermentation to stress, the protein component having a
concentration sufficient to substantially increase the surface
activity of the one or more surfactants relative to the surface
activity of the one or more surfactants in the absence of the
protein component, and combining the detersive surfactant, adjunct
detergent ingredient, and protein component to obtain a liquid
detergent composition.
2. The method of claim 1, wherein said detersive surfactant further
comprises a nonionic surfactant or an anionic surfactant.
3. The method of claim 1, wherein said adjunct detergent
ingredients comprise one or more neutralizer selected from the
group consisting of monoethanolamine (MEA), diethanolamine (DEA),
and triethanolamine (TEA).
4. The method of claim 1, wherein said adjunct detergent
ingredients comprise a hydrotropic agent.
5. The method of claim 4, wherein said hydrotropic agent comprises
ethanol.
6. The method of claim 1, wherein said adjunct detergent
ingredients comprise a protein stabilizer.
7. The method of claim 6, wherein said protein stabilizer comprises
one or more of propylene glycol or borax.
8. The method of claim 1, wherein the mixture of multiple
intracellular proteins comprises the product of a fermentation of a
plurality of yeast cells in the presence of a nutrient source.
9. The method of claim 1, wherein the fermenting yeast cells
comprise one or more of saccharomyces cerevisiae, kluyveromyces
marxianus, kluyveromyces lactis, candida utilis, zygosaccharomyces,
pichia, or hansanula.
10. The method of claim 8, wherein the nutrient source comprises a
sugar.
11. The method of claim 10, wherein the nutrient source further
comprises one or more of diastatic malt, diammonium phosphate,
magnesium sulfate, ammonium sulfate zinc sulfate, and ammonia.
12. The method of claim 1, wherein the detersive surfactant package
comprises a total surfactant concentration of from about 6% by
weight to about 24% by weight.
13. The method of claim 1, wherein the stress is selected from the
group consisting of heat stress, chemical stress, and physical
stress.
14. A method of making a liquid detergent, comprising: providing a
detersive surfactant package of one or more surfactants; providing
at least one adjunct detergent ingredient, providing a protein
component comprising a mixture of multiple intracellular proteins,
at least a portion of the mixture including yeast polypeptides
obtained from fermenting yeast cells and yeast heat shock proteins
resulting from subjecting a mixture obtained from the yeast
fermentation to stress, the protein component having a
concentration sufficient to substantially increase the surface
activity of the one or more surfactants relative to the surface
activity of the one or more surfactants in the absence of the
protein component, and combining the detersive surfactant, adjunct
detergent ingredient, and protein component to obtain a liquid
detergent composition, wherein the detersive surfactant package
comprises a total surfactant concentration of from about 6% by
weight to about 24% by weight.
15. The method of claim 14, wherein said detersive surfactant
further comprises a nonionic surfactant or an anionic
surfactant.
16. The method of claim 14, wherein said adjunct detergent
ingredients comprise a protein stabilizer.
17. The method of claim 14, wherein the stress is selected from the
group consisting of heat stress, chemical stress, and physical
stress.
18. A method of making a liquid detergent, comprising: providing a
detersive surfactant package of one or more surfactants; providing
at least one adjunct detergent ingredient, providing a protein
component comprising a mixture of multiple intracellular proteins,
at least a portion of the mixture including yeast polypeptides
obtained from fermenting yeast cells and yeast heat shock proteins
resulting from subjecting a mixture obtained from the yeast
fermentation to stress, the protein component having a
concentration sufficient to substantially increase the surface
activity of the one or more surfactants relative to the surface
activity of the one or more surfactants in the absence of the
protein component, and combining the detersive surfactant, adjunct
detergent ingredient, and protein component to obtain a liquid
detergent composition, wherein the stress is selected from the
group consisting of heat stress, chemical stress, and physical
stress.
19. The method of claim 18, wherein said detersive surfactant
further comprises a nonionic surfactant or an anionic
surfactant.
20. The method of claim 18, wherein said adjunct detergent
ingredients comprise a protein stabilizer.
Description
FIELD OF THE INVENTION
[0001] This invention relates to surfactant mixtures with improved
surface-active properties, and methods of making and using the
same. More particularly, this invention relates to surfactant
compositions containing a protein component that has the effect of
improving the surface-active properties of the surfactants
contained in the compositions.
BACKGROUND OF THE INVENTION
[0002] Surfactants (also called surface active agents or wetting
agents) are organic chemicals that reduce surface tension in water
and other liquids. There are hundreds of compounds that can be used
as surfactants. These compounds are usually classified by their
ionic behavior in solutions: anionic, cationic, non-ionic or
amphoteric (zwitterionic). Each surfactant class has its own
specific physical, chemical, and performance properties.
[0003] Surfactants are compounds composed of both hydrophilic and
hydrophobic or lipophobic groups. In view of their dual hydrophilic
and hydrophobic nature, surfactants tend to concentrate at the
interfaces of aqueous mixtures; the hydrophilic part of the
surfactant orients itself towards the aqueous phase and the
hydrophobic parts orients itself away from the aqueous phase into
the second phase.
[0004] The hydrophobic part of a surfactant molecule is generally
derived from a hydrocarbon containing 8 to 20 carbon atoms (e.g.
fatty acids, paraffins, olefins, alkylbenzenes). The hydrophilic
portion may either ionize in aqueous solutions (cationic, anionic)
or remain un-ionized (non-ionic). Surfactants and surfactant
mixtures may also be amphoteric or zwitterionic.
[0005] Surfactants are known for their use in personal care
products (e.g., soaps, specialty soaps, liquid hand soaps,
shampoos, conditioners, shower gels, dermatology and acne care
products), household products (e.g., dry and liquid laundry
detergents, dish soaps, dishwasher detergents, toilet bowl
cleaners, upholstery cleaners, fabric softeners), hard surface
cleaners (floor cleaners, metal cleaners, automobile and other
vehicle cleaners), pet care products (e.g., shampoos), and cleaning
products in general. Other uses are in industrial applications in
lubricants, emulsion polymerisation, textile processing, mining
flocculates, petroleum recovery, wastewater treatment and many
other products and processes. Surfactants are also used as
dispersants after oil spills.
SUMMARY OF THE INVENTION
[0006] The present invention relates to the use of a protein
component that is used as an additive to surfactant-containing
compositions, particularly detergents, in order to improve the
surface-active properties of the surfactants. In this way, the
surfactant-containing compositions may be made more effective, or
they may be formulated to have a lower concentration of surfactants
than would otherwise be needed to achieve a desired level of
surface-activity.
[0007] The protein component preferably comprises a variety of
proteins produced by an aerobic yeast fermentation process. The
aerobic yeast fermentation process is conducted within a reactor
having aeration and agitation mechanisms, such as aeration tubes
and/or mechanical agitators. The starting materials (liquid growth
medium, yeast, sugars, additives) are added to the fermentation
reactor and the fermentation is conducted as a batch process. After
fermentation, the fermentation product may be subjected to
additional procedures intended to increase the yield of proteins
produced from the process. Examples of these additional procedures
include heat shock of the fermentation product, physical and/or
chemical disruption of the yeast cells to release additional
polypeptides, lysing of the yeast cells, or other procedures
described herein and/or known to those of skill in the art. The
yeast cells are removed by centrifugation or filtration to produce
a supernatant containing the protein component.
[0008] The protein component produced by the above fermentation
process comprises a large number of proteins having a variety of
molecular weights. Although the entire composition of proteins may
be useful for improving surface-active properties of surfactants,
the inventors have found that the proteins having molecular weights
in the range of about 100 to about 450,000, and preferably from
about 500 to about 50,000 daltons (as indicated by results of
polyacrylamide gel electrophoresis), are sufficient to achieve
desirable results.
[0009] Although the protein component of the present invention is
preferably obtained by the foregoing fermentation process, the
component may also be obtained by alternative methods, including
direct synthesis or isolation of the proteins from other naturally
occurring sources.
[0010] The protein component is preferably added to compositions
containing surfactants in order to improve the surface-active
properties of the surfactants and, in fact, to change the nature of
the surface-active properties of the surfactants. For example, the
protein component may advantageously be used as an additive to
detergent compositions, which comprise a detersive surfactant
system and adjunct detergent ingredients. Several (non-limiting)
embodiments of detergent compositions include personal care
products (e.g., soaps, specialty soaps, liquid hand soaps,
shampoos, conditioners, shower gels, dermatology and acne care
products), household products (e.g., dry and liquid laundry
detergents, dish soaps, dishwasher detergents, toilet bowl
cleaners, upholstery cleaners, fabric softeners), hard surface
cleaners (floor cleaners, metal cleaners, automobile and other
vehicle cleaners), pet care products (e.g., shampoos), and cleaning
products in general. As will be appreciated by those of ordinary
skill in the art, the foregoing list of embodiments is not intended
to be exclusive, as the advantages obtained by the use of the
protein mixture described herein may be applied to any detergent
composition or other surfactant-containing composition.
[0011] The addition of the protein mixture of the present invention
to a surfactant-containing composition has the effect of improving,
increasing, and enhancing the surface-active properties of the
surfactants contained in the composition. This effect has
particular advantages in applications in which surface-active
properties of surfactants in compositions are desired, including
the detergent compositions discussed herein.
DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS
[0012] The compositions of the present invention include a protein
component used in combination with a surfactant-containing
composition--for example, a detergent--to improve, increase, and
enhance the surface-active properties of the surfactants contained
in the composition. Thus, the methods of the present invention
includes a method for improving the surface-active properties of
surfactants contained in a composition by incorporating a protein
component within the composition.
Protein Component
[0013] As used herein, the term "protein component" refers to a
mixture of proteins that includes a number of proteins having a
molecular weight of between about 100 and about 450,000 daltons,
and most preferably between about 500 and about 50,000 daltons, and
which, when combined with one or more surfactants, enhances the
surface-active properties of the surfactants.
[0014] In a first example, the protein component comprises the
supernatant recovered from an aerobic yeast fermentation process.
Yeast fermentation processes are generally known to those of skill
in the art, and are described, for example, in the chapter entitled
"Baker's Yeast Production" in Nagodawithana T. W. and Reed G.,
Nutritional Requirements of Commercially Important Microorganisms,
Esteekay Associates, Milwaukee, Wis., pp 90-112 (1998), which is
hereby incorporated by reference. Briefly, the aerobic yeast
fermentation process is conducted within a reactor having aeration
and agitation mechanisms, such as aeration tubes and/or mechanical
agitators. The starting materials (e.g., liquid growth medium,
yeast, a sugar or other nutrient source such as molasses, corn
syrup, or soy beans, diastatic malt, and other additives) are added
to the fermentation reactor and the fermentation is conducted as a
batch process.
[0015] After fermentation, the fermentation product may be
subjected to additional procedures intended to increase the yield
of the protein component produced from the process. Several
examples of post-fermentation procedures are described in more
detail below. Other processes for increasing yield of protein
component from the fermentation process may be recognized by those
of ordinary skill in the art.
[0016] Saccharomyces cerevisiae is a preferred yeast starting
material, although several other yeast strains may be useful to
produce yeast ferment materials used in the compositions and
methods described herein. Additional yeast strains that may be used
instead of or in addition to Saccharomyces cerevisiae include
Kluyveromyces marxianus, Kluyveromyces lactis, Candida utilis
(Torula yeast), Zygosaccharomyces, Pichia, Hansanula, and others
known to those skilled in the art.
[0017] In the first embodiment, saccharomyces cerevisiae is grown
under aerobic conditions familiar to those skilled in the art,
using a sugar, preferably molasses or corn syrup, soy beans, or
some other alternative material (generally known to one of skill in
the art) as the primary nutrient source. Additional nutrients may
include, but are not limited to, diastatic malt, diammonium
phosphate, magnesium sulfate, ammonium sulfate zinc sulfate, and
ammonia. The yeast is preferably propagated under continuous
aeration and agitation between 30 degrees to 35 degrees C. and at a
pH of 4.0 to 6.0. The process takes between 10 and 25 hours and
ends when the fermentation broth contains between 4 and 8% dry
yeast solids, (alternative fermentation procedures may yield up to
15-16% yeast solids), which are then subjected to low food-to-mass
stress conditions for 2 to 24 hours. Afterward, the yeast
fermentation product is centrifuged to remove the cells, cell
walls, and cell fragments. It is worth noting that the yeast cells,
cell walls, and cell fragments will also contain a number of useful
proteins suitable for inclusion in the protein component described
herein.
[0018] In an alternative embodiment, the yeast fermentation process
is allowed to proceed until the desired level of yeast has been
produced. Prior to centrifugation, the yeast in the fermentation
product is subjected to heat-stress conditions by increasing the
heat to between 40 and 60 degrees C., for 2 to 24 hours, followed
by cooling to less than 25 degrees C. The yeast fermentation
product is then centrifuged to remove the yeast cell debris and the
supernatant, which contains the protein component, is
recovered.
[0019] In a further alternative embodiment, the fermentation
process is allowed to proceed until the desired level of yeast has
been produced. Prior to centrifugation, the yeast in the
fermentation product is subjected to physical disruption of the
yeast cell walls through the use of a French Press, ball mill,
high-pressure homogenization, or other mechanical or chemical means
familiar to those skilled in the art, to aid the release of
intracellular, polypeptides and other intracellular materials. It
is preferable to conduct the cell disruption process following a
heat shock, pH shock, or autolysis stage. The fermentation product
is then centrifuged to remove the yeast cell debris and the
supernatant is recovered.
[0020] In a still further alternative embodiment, the fermentation
process is allowed to proceed until the desired level of yeast has
been produced. Following the fermentation process, the yeast cells
are separated out by centrifugation. The yeast cells are then
partially lysed by adding 2.5% to 10% of a surfactant to the
separated yeast cell suspension (10%-20% solids). In order to
diminish the protease activity in the yeast cells, 1 mM EDTA is
added to the mixture. The cell suspension and surfactants are
gently agitated at a temperature of about 25.degree. to about
35.degree. C. for approximately one hour to cause partial lysis of
the yeast cells. Cell lysis leads to an increased release of
intracellular proteins and other intracellular materials. After the
partial lysis, the partially lysed cell suspension is blended back
into the ferment and cellular solids are again removed by
centrifugation. The supernatant, containing the protein component,
is then recovered.
[0021] In a still further alternative embodiment, fresh live
Saccharomyces cerevisiae is added to a jacketed reaction vessel
containing methanol-denatured alcohol. The mixture is gently
agitated and heated for two hours at 60 degrees C. The hot slurry
is filtered and the filtrate is treated with charcoal and stirred
for 1 hour at ambient temperature, and filtered. The alcohol is
removed under vacuum and the filtrate is further concentrated to
yield an aqueous solution containing the protein component.
[0022] In a still further alternative embodiment, the protein
component is further refined so as to isolate the proteins having a
molecular weight of between about 100 and about 450,000, and
preferably between about 500 and about 50,000 daltons, utilizing
Anion Exchange Chromatography of the fermentation supernatant,
followed by Molecular Sieve Chromatography. The refined protein
component is then utilized in the compositions and methods
described herein.
[0023] In a still further alternative embodiment, preservatives and
stabilizers are added to the protein component compositions and the
pH is adjusted to between 3.8 and 4.8 to provide long-term
stability to the compositions.
[0024] The foregoing descriptions provide examples of a protein
component suitable for use in the compositions and methods
described herein. These examples are not exclusive. For example,
those of skill in the art will recognize that the protein component
may be obtained by isolating suitable proteins from an alternative
protein source, by synthesis of proteins, or by other suitable
methods. The foregoing description is not intended to limit the
term "protein component" only to those examples included
herein.
[0025] Additional details concerning the fermentation processes and
other aspects of the protein component are described in U.S. patent
application Ser. No. 10/799,529, filed Mar. 11, 2004, entitled
"Altering Metabolism in Biological Processes," which is assigned to
the assignee of the present application. Still further details
concerning these processes and materials are described in U.S.
patent application Ser. No. 09/948,457, filed Sep. 7, 2001,
entitled "Biofilm Reduction in Crossflow Filtration Systems," which
is also assigned to the assignee of the present application. Each
of these United States patent applications is hereby incorporated
by reference herein in its entirety.
Surfactants
[0026] The detergent compositions described herein include one or
more surfactants at a wide range of concentration levels. Some
examples of surfactants that are suitable for use in the detergent
compositions described herein include the following: [0027]
Anionic: Sodium linear alkylbenzene sulphonate (LABS); sodium
lauryl sulphate; sodium lauryl ether sulphates; petroleum
sulphonates; linosulphonates; naphthalene sulphonates, branched
alkylbenzene sulphonates; linear alkylbenzene sulphonates; alcohol
sulphates. [0028] Cationic: Stearalkonium chloride; benzalkonium
chloride; quaternary ammonium compounds; amine compounds. [0029]
Non-ionic: Dodecyl dimethylamine oxide; coco diethanol-amide
alcohol ethoxylates; linear primary alcohol polyethoxylate;
alkylphenol ethoxylates; alcohol ethoxylates; EO/PO polyol block
polymers; polyethylene glycol esters; fatty acid alkanolamides.
[0030] Amphoteric: Cocoamphocarboxyglycinate;
cocamidopropylbetaine; betaines; imidazolines.
[0031] In addition to those listed above, suitable nonionic
surfactants include alkanolamides, amine oxides, block polymers,
ethoxylated primary and secondary alcohols, ethoxylated
alkylphenols, ethoxylated fatty esters, sorbitan derivatives,
glycerol esters, propoxylated and ethoxylated fatty acids,
alcohols, and alkyl phenols, alkyl glucoside glycol esters,
polymeric polysaccharides, sulfates and sulfonates of ethoxylated
alkylphenols, and polymeric surfactants. Suitable anionic
surfactants include ethoxylated amines and/or amides,
sulfosuccinates and derivatives, sulfates of ethoxylated alcohols,
sulfates of alcohols, sulfonates and sulfonic acid derivatives,
phosphate esters, and polymeric surfactants. Suitable amphoteric
surfactants include betaine derivatives. Suitable cationic
surfactants include amine surfactants. Those skilled in the art
will recognize that other and further surfactants are potentially
useful in the compositions depending on the particular detergent
application.
[0032] Preferred anionic surfactants used in some detergent
compositions include CalFoam.TM. ES 603, a sodium alcohol ether
sulfate surfactant manufactured by Pilot Chemicals Co., and
Steol.TM. CS 460, a sodium salt of an alkyl ether sulfate
manufactured by Stepan Company. Preferred nonionic surfactants
include Neodol.TM. 25-7 or Neodol.TM. 25-9, which are C12-C15
linear primary alcohol ethoxylates manufactured by Shell Chemical
Co., and Genapol.TM. .apprxeq.L-60, which is a C12-C16 natural
linear alcohol ethoxylated to 60E C cloud point (approx. 7.3 mol),
manufactured by Hoechst Celanese Corp.
[0033] Several of the known surfactants are non-petroleum based.
For example, several surfactants are derived from naturally
occurring sources, such as vegetable sources (coconuts, palm,
castor beans, etc.). These naturally derived surfactants may offer
additional benefits such as biodegradability.
[0034] It should be understood that these surfactants and the
surfactant classes described above are identified only as preferred
materials and that this list is neither exclusive nor limiting of
the compositions and methods described herein.
Detergent Compositions
[0035] The detergent compositions described herein generally
comprise a detersive surfactant system and adjunct detergent
ingredients. As those of skill in the art will recognize, the
formulation of a given detergent composition will depend upon its
intended use. Examples of such uses include personal care products
(e.g., soaps, specialty soaps, liquid hand soaps, shampoos,
conditioners, shower gels, dermatology and acne care products),
household products (e.g., dry and liquid laundry detergents, dish
soaps, dishwasher detergents, toilet bowl cleaners, upholstery
cleaners, fabric softeners), hard surface cleaners (floor cleaners,
metal cleaners, automobile and other vehicle cleaners), pet care
products (e.g., shampoos), and cleaning products in general.
[0036] The detersive surfactant system may include any one or
combination of the surfactant classes and individual surfactants
described in the previous section and elsewhere herein, or other
surfactant classes and individual surfactants known to those of
skill in the art. For example, a typical liquid laundry detergent
will include a combination of anionic and nonionic surfactants as
the detersive surfactant system. Nonionic surfactants generally
give good detergency on oily soil, whereas anionic surfactants
generally give good detergency on particulate soils and contribute
to formulation stability.
[0037] The adjunct detergent ingredients may include any of a range
of additives that are advantageous for obtaining a desired
beneficial property. For example, a typical liquid laundry
detergent will include neutralizers such as monoethanolamine (MEA),
diethanolamine (DEA), or triethanolamine (TEA); hydrotropic agents
such as ethanol; enzyme stabilizers such as propylene glycol and/or
borax; and other additives. Detergent compositions are generally
known to those of skill in the art. As used herein, the term
"conventional detergent" refers to detergent compositions currently
available either commercially or by way of formulations available
from the literature. Examples of "conventional detergents" include
"conventional liquid laundry detergents," "conventional hand
soaps," and others of the "conventional" detergents described
herein.
Effect on Critical Micelle Concentration
[0038] A number of experiments were performed in which it was
observed that the combination of the protein component with a
surfactant-containing composition caused a downward shift in the
critical micelle concentration (CMC) relative to that of the
surfactant-containing composition without the protein component.
CMC is the characteristic concentration of surface active agents
(surfactants) in solution above which the appearance and
development of micelles brings about sudden variation in the
relation between the concentration and certain physico-chemical
properties of the solution (such as the surface tension). Above the
CMC the concentration of singly dispersed surfactant molecules is
virtually constant and the surfactant is at essentially its optimum
of activity for many applications.
[0039] The table below shows the results of CMC measurements on a
sample containing surfactant alone (Sample A), and two samples
containing surfactant and a protein component (Samples B and C).
All tests were conducted in duplicate, by standard surface tension
as a function of concentration experimentation using a Kruss
Processor Tensiometer K12 with an attached automated dosing
accessory. For each test a high concentration stock solution was
incrementally dosed into pure distilled water, whilst measuring
surface tension at each successive concentration.
TABLE-US-00001 Critical Micelle Concentration Values for Samples in
Pure Distilled Water (on a ppm of sample basis) Sample Test # CMC
(ppm) Sample A Test 1 443 (Surfactant without Test 2 440 protein
component) Average 442 Sample B Test 1 74.6 (Surfactant with
protein Test 2 75.3 component) Average 75.0 Sample C Test 1 59.8
(Surfactant with protein Test 2 60.1 component) Average 60.0
[0040] The compositions utilized in the above samples were the
following:
TABLE-US-00002 Concentration (% by weight) Sample Samples Component
A B & C Water 84.92 64.92 Protein Component (Samples B and C
only) 0 20.0 (Product of fermentation of saccharomyces cerevisiae,
without additional processing) Inorganic salts 0.31 0.31 (e.g.,
diammonium phosphate, ammonium sulfate, magnesium sulfate, zinc
sulfate, calcium chloride) Neodol .TM. 25-7 7.5 7.5 (Non-ionic
surfactant) Steol .TM. CS 460 1.5 1.5 (Anionic surfactant)
Propylene glycol 5.27 5.27 Methyl paraben 0.15 0.15 Propyl paraben
0.05 0.05 Sodium benzoate 0.15 0.15 BHA 0.02 0.02 BHT 0.02 0.02
Ascorbic acid 0.11 0.11 100.00 100.00
As the foregoing results demonstrated, the addition of the protein
component to Samples B and C caused up to a seven-fold downward
shift in the CMC value for the surfactant-containing composition.
In effect, the protein component increases the surface-active
properties of the surfactants contained in the composition.
[0041] The downward shift in CMC value obtained by incorporating
the protein component in a surfactant-containing composition has
substantial utility for use in detergent compositions such as those
described herein. In particular, the downward shift of CMC value
for a given detersive surfactant or surfactant package in the
presence of the protein component means that the surfactant(s)
demonstrate an improved, increased, or enhanced level of
surface-active properties. Thus, for a given detergent composition,
the incorporation of the protein component in the composition makes
it possible to obtain a greater level of surface-activity from the
surfactants contained in the composition than would be obtained
from the unmodified detergent composition. Alternatively, it would
be possible to reduce the level of surfactant(s) contained in the
detergent composition without sacrificing the level of
surface-activity of the composition, or its cleaning ability.
[0042] For example, a conventional premium liquid laundry detergent
formulation includes about 25% to about 40% by weight of
surfactants. One such formulation, having 36% surfactants by
weight, is reproduced below:
TABLE-US-00003 Premium Liquid Laundry Detergent Formulation
Ingredients % Wt Function Trade Name Water 53.36 Boric acid 1.10
Enzyme stabilizer Sodium gluconate 0.70 Enzyme stabilizer Propylene
glycol 3.00 Enzyme stabilizer EtOH 3A 3.00 Hydrotrope AG (50%) 5.80
Surfactant Glucopon 625 UP AE 5.20 Surfactant Neodol 25-7 FAES
25.00 Surfactant Texapon N-70 Optical brightener 0.14 UV whitening
agent Sodium hydroxide, 50% 0.50 Neutralizer Monoethanolamine 0.50
Buffer Protease 0.75 Enzyme Savinase 16.0L Amylase 0.95 Enzyme
Termylase 300L Preservative/optical as brightener needed
(T. Morris, S. Gross, M. Hansberry, "Formulating Liquid Detergents
for Multiple Enzyme Stability," Happi, January 2004, pp. 92-98). By
incorporating the protein component described herein in a
formulation such as the liquid laundry detergent listed above, it
is possible to reduce the surfactant levels by at least 40%, and up
to about 75% or more, while retaining a comparable CMC value for
the laundry detergent composition and without sacrificing the
cleaning performance of the formulation. Similar results may be
obtained by incorporating the protein component in other detergent
compositions, including all of those described elsewhere
herein.
[0043] Thus, in addition to the compositions described herein,
there are also described methods for improving, enhancing, and/or
increasing the surface-active properties of surfactants in
surfactant-containing compositions, and methods for reducing the
levels of surfactants required for surfactant-containing
compositions such as the detergent compositions described herein.
In all of these methods, the beneficial results are obtained by the
inclusion of a suitable protein component in the detergent
composition. The resulting compositions will have CMC values and
cleaning efficiency that are comparable to, or better than, the
unmodified compositions.
Conversion of Grease to Surface-Active Material
[0044] Experiments were performed in which it was observed that the
protein component, when used in combination with one or more
surfactants, had the effect of converting greasy waste contaminants
to surface active materials. In the experiments, a composition
including surfactants and a protein component was added to diluted
waste activated sludge (WAS), followed by observation of the volume
of a bacon grease droplet in the composition. Interfacial tension
reduction was confirmed to be by the creation of surfactant-like
(interfacially active) materials, by checking the critical micelle
concentration of the retains and noting that the critical micelle
concentration was, in fact, reduced after exposure of the solution
to the bacon grease.
[0045] In the following experiments, a small droplet of grease was
formed on the end of a capillary tip within a bulk phase of the
sample aqueous solution being studied. Measurements of interfacial
tension between the droplet and the aqueous phase and of droplet
volume were made as a function of elapsed time by optical pendant
drop interfacial analysis using a Kruss Drop Shape Analysis
System.
[0046] Trial 1: Grease Droplet in Aqueous Solutions
[0047] In a first experiment, a 5.0 microliter droplet of bacon
grease was placed in a 5.0 milliliter aqueous solution and allowed
to reach equilibriums for interfacial tension and droplet volume.
In a first case, the aqueous solution was pure water. In a second,
the aqueous solution contained 10 ppm of the Sample A formulation
(surfactant-containing composition with no protein component). In a
third, the aqueous solution contained 10 ppm of the Sample B
formulation (surfactant-containing composition with protein
component). The results are as follows.
TABLE-US-00004 Effect of Aqueous Solutions at 5.0 ml on a 5.0
microliter Bacon Grease Droplet Initial Equilibrium Time Elapsed
Interfacial Interfacial for Intervacial Time Elapsed Tension with
Tension with Tension Equilibrium for Volume Aqueous Bacon Grease
Bacon Grease Equilibration Grease Drop Equilibration Solution
(mN/m) (mN/m) (minutes) Volume (ul) (minutes) Sample B 15.80 7.06
1300 4.44 1300 (10 ppm) Sample A 18.20 17.35 30 4.92 500 (10 ppm)
Pure water 25.34 25.32 NA 5.00 NA
TABLE-US-00005 Effect of 5.0 microliter Bacon Grease Droplet on 5.0
ml Aqueous Solutions Initial Surface Tension CMC No CMC Found
Surface After Grease Grease Starting with Aqueous Tension Exposure
Exposure Grease Exposed Solution (mN/m) (mN/m) (ppm) Retain (ppm)
Sample B 64.12 39.01 75 35 (10 ppm) Sample A 71.60 71.57 442 442
(10 ppm) Pure Water 72.50 72.48 NA NA
[0048] Several conclusions were drawn from the above data. First,
it was noted that pure water had no effect on the bacon grease, nor
did the bacon grease have any effect on the pure water.
[0049] An additional conclusion drawn from the above data was that,
with the surfactant package alone (Sample A, without the protein
component), about 1.6% of the bacon grease volume (0.08 ul of 5.0
ul) is lost into the aqueous phase. However, it was concluded that
this effect was due to emulsification of hydrophobic grease by the
surfactants involved, and that it did not result in any significant
increase in the amount of surfactant-like material available in the
aqueous phase. This conclusion was based on three of the parameters
listed above. First, the surface tension of the retain, after bacon
grease exposure, was not significantly lower than the surface
tension of the same aqueous solution before bacon grease exposure
(as it would be if surface-active materials were added to the
aqueous phase). Second, the CMC for the additives in the aqueous
phase was unaffected by bacon grease exposure (it would be expected
to decrease if significant amounts of new surface-active materials
were created due to exposure to the grease). Third, the interfacial
tension decay of the surfactant-only sample (Sample A) lasted about
30 minutes, whereas the loss of grease droplet volume in the Sample
A solution lasted about 500 minutes, during which time the
interfacial tension was already equilibrated. If the grease volume
going into the aqueous phase was providing extra soluble
surfactants to the aqueous phase, the interfacial tension would
have been expected to continue to decay during the loss of grease
droplet volume. This would be expected unless the interface between
the grease droplet and the water was saturated with surfactant, so
that added soluble surfactant to the aqueous phase could not go to
that interface. However, at an interfacial tension of 17.35 mN/m,
it is not possible that the interface was saturated with
surfactant. Therefore, the emulsification of hydrophobic grease is
the only reasonable explanation for the 1.6% grease lost in the
Sample A data above.
[0050] Yet another conclusion drawn from the above data is that, in
the Sample B case, which includes a surfactant-containing
composition including a protein component, the much longer term and
more substantial interfacial tension and grease droplet volume
decay suggest that new interfacial active species are being
generated by breakdown of the grease. This is shown, for example,
by the much lower surface tensions determined for the retain
solutions following grease drop exposure as well as the much lower
CMC found when further concentrating the same retains. For example,
by mass balance, it was known that 0.56 ul of the grease (11.2% of
the original grease drop volume) passed into the 5.0 ml aqueous
solution containing 10 ppm of Sample B after 24 hours. This
represents a 112 ppm concentration of former grease materials in
the aqueous phase. The CMC of the aqueous phase was then found to
be 35 ppm, as opposed to 75 ppm for the aqueous Sample B
composition alone. Thus, the CMC decreases by 40 ppm due to the
presence of 112 ppm of former grease materials being taken into the
water phase. Stated in other terms, 40/112, or 35.7% of the 11.2%
of the grease drop materials lost from the grease droplet became
surfactant-like, interfacially active species with the cleaning
power of the order of the cleaning power of the Sample B
formulation. This calculates as 4% of the grease being made into
materials capable of cleaning more grease, as opposed to 0% in
either the case of pure water alone, or in the case of the
surfactant package only (Sample A) Finally, in the Sample B case,
the interfacial tension decay and the grease drop volume decay
followed the same time dependence, and the interfacial tension
decay ceased at about 7.06 mN/m. These data indicate that the
conversion of grease reaction had ceased after about 1300 minutes
without the interface between the grease and the solution being
saturated, which would happen at a lower interfacial tension.
[0051] Trial 2: Grease Droplet in Waste Activated Sludge
[0052] In a second experiment, a 5.0 microliter droplet of bacon
grease was placed in a 5.0 milliliter in a 1:10 diluted aqueous
mixture of waste activated sludge (WAS) and allowed to reach
equilibriums for interfacial tension and droplet volume. In a first
case, the aqueous solution contained only WAS. In a second, the
aqueous solution also contained 10 ppm of the Sample B formulation
(surfactant-containing composition with protein component). The
results are as follows.
TABLE-US-00006 Effect of Aqueous Solutions at 5.0 ml on a 5.0
microliter Bacon Grease Droplet Initial Equilibrium Time Elapsed
Diluted 1:10 Interfacial Interfacial for Intervacial Time Elapsed
WAS Tension with Tension with Tension Equilibrium for Volume
Aqueous Bacon Grease Bacon Grease Equilibration Grease Drop
Equilibration Solution (mN/m) (mN/m) (minutes) Volume (ul)
(minutes) Diluted WAS 23.20 20.12 g.t. 2880 4.79 g.t. 2880 Sample B
14.50 3.50 2500 3.57 g.t. 2880 (10 ppm)
TABLE-US-00007 Effect of 5.0 microliter Bacon Grease Droplet on 5.0
ml Aqueous Solutions Diluted Initial Surface Tension CMC No CMC
Found 1:10 WAS Surface After Grease Grease Starting with Aqueous
Tension Exposure Exposure Grease Exposed Solution (mN/m) (mN/m)
(ppm) Retain (ppm) Diluted 66.81 57.07 NA NA WAS Sample B 60.13
25.72 68 4 (10 ppm)
[0053] Again, several conclusions were drawn from the above data.
First, in both systems, it is apparent that grease is converted to
interfacially active materials. However, the conversion of grease
to interfacially active materials was much more substantial with
the 10 ppm of Sample B present in the diluted WAS, relative to the
diluted WAS alone. Further, the conversion of grease to
interfacially active materials by the Sample B formulation was much
more substantial in the diluted WAS than it was in pure water.
Still further, sufficient grease conversion takes place in the
Sample B case to saturate the aqueous phase/grease droplet
interface, at an interfacial tension of about 3.50 mN/m, while the
conversion reaction continued to add more interfacially active
species to the bulk of the 10 ppm Sample B phase.
[0054] Turning to the data, the diluted WAS was found to have a
surface tension of 66.81 mN/m, before exposure to the bacon grease,
which is below that of pure water (72.5 mN/m). This indicated that
the diluted WAS contained some surface active species on its own.
Those surface active species were also found to be interfacially
active--e.g., the initial interfacial tension between the diluted
WAS and the bacon grease was found to be 23.20 mN/m, below that of
the interfacial tension between pure water and bacon grease (25.34
mN/m).
[0055] Duplicate 48 hour interfacial tension experiments were run
with the diluted WAS against 5.0 ul grease drops, using 5.0 ml of
diluted WAS for each experiment. Interfacial tension decay was
observed in both trials, as compared to a complete absence of
interfacial decay observed in the pure water case. The decay was
from 23.50 mN/m to 20.12 mN/m. In addition, loss of grease volumes
was observed, from 5.0 ul to 4.79 ul. Accordingly, about 4.2% of
the grease was lost to the aqueous phase, making the converted
grease material concentration in the aqueous phase about 42 ppm, at
2880 minutes. The time frame for equilibration was roughly the same
for both interfacial tension and for volume decay. Also, the
equilibration times were too long to be caused by simple
pre-existing surfactant equilibration at the interface. Thus, it
was presumed that a reaction mechanism was at work, and that
creation of interfacially active species from the grease was
occurring.
[0056] The retains contained additional interfacially active
material. Thus, the WAS itself was converting grease to
interfacially active material. This is apparent not only from the
time dependent data above, but also from the fact that the retains
show surface tensions which average 57.07 mN/m--down from 66.81
mN/m before grease exposure. It was presumed, however, that
insufficient amounts of interfacially active material were created
to determine a CMC value for those materials alone.
[0057] Turning to the Sample B trials, the interfacial tension
decay was from an initial value of 14.50 mN/m--a value lower than
the initial interfacial tension for 10 ppm of Sample B in pure
water, due to the interfacially active materials initially present
in the WAS--to an equilibrium value of 3.5 mN/m in 2500 minutes.
The fact that the grease volume loss continued out beyond the 2880
minute elapsed time period was due to the interface becoming
saturated with the interfacially active materials formed in the
2500 minute time frame. As further support for this conclusion,
after 48 hours of grease exposure the surface tension for the
retain solutions were 25.72 mN/m. This is such a low surface
tension that the solution was cleraly beyond its CMC. Thus, at that
point, one would expect the grease drop interface to be saturated
with interfacially active materials.
[0058] The initial surface tension for the 10 ppm Sample B
formulation in diluted WAS was 60.13 mN/m, which was lower than the
value in pure water (64.12 mN/m, as above). This was due to the
interfacially active materials initially present in the WAS. The
25.72 mN/m average retain surface tension was, however, much lower
than the 39.01 mN/m average retain surface tension from the pure
water trials.
[0059] The 10 ppm Sample B retains contained so much surfactant
added to it from the grease breakdown that its concentration was
above the CMC. Therefore, the retains CMC determination was made by
diluting the retains with WAS. The results indicated a CMC of only
4 ppm in the presence of the surfactant-materials created from the
breakdown of the grease. This value may be compared to the CMC for
the 10 ppm Sample B formula in WAS with no grease exposure--68
ppm.
[0060] Thus, a mass balance was performed based upon the grease
volume lost. The volume decrease from the grease droplet was 1.43
ul (5.0 ul minus 3.57 ul) in 2880 minutes, which grease volume was
added to the WAS phase retains. This amounted to 28.6% of the
grease, or 286 ppm. The CMC decrease, relative to the 10 ppm Sample
B formulation, was 68-4=64 ppm. Stated otherwise, the CMC decreased
by 64 ppm due to 286 ppm of the former grease materials being taken
into the WAS phase. Thus, 64/286, or 22.4% of the 28.6% of the
grease drop materials lost from the grease droplet.become
surfactant-like, interfacially active species, with the cleaning
power of the order of the cleaning power of the Sample B
formulation.
[0061] This calculates as 6.4% of the grease being made into
materials capable of cleaning more grease (interfacially active
species), for a 28.6% loss in the overall grease volume, for 10 ppm
of the Sample B formulation in diluted WAS. These values are
properly compared to 4.0% of the grease being made into
interfacially active species for an 11.2% loss of overall grease
volume for the 10 ppm of Sample B formulation in pure water. The
diluted WAS alone showed a 4.2% loss of overall grease volume, with
an undetermined amount of interfacially active species created.
Pure water caused no grease loss (0%), and no interfacially active
species development. The surfactant package alone (Sample A),
caused a 1.6% grease loss, but no development of interfacially
active materials.
[0062] The values for decrease in grease volume (i.e., % of a 5.0
ul drop lost due to exposure to 5 ml of the "cleaning" solution)
are significant in terms of grease removal. In addition, the values
for conversion of the grease into interfacially active materials
capable of emulsifying grease are also significant, as they
represent an autocatalytic grease removal process. These values are
presented in the table below.
TABLE-US-00008 Effect of Various Solutions at 5.0 ml on a 5.0 ul
Grease Drop Grease Lost to Grease Converted to Aqueous Solution
Aqueous Phase Interfacially Active Materials Pure Water 0% 0%
Sample A (10 ppm) 1.5% 0% in Pure Water Sample B (10 ppm) 11.2%
4.0% in Pure Water Diluted (1:10) WAS 4.2% NA Sample B (10 ppm)
28.6% 6.4% in Diluted (1:10) WAS
Effects on Contaminants
[0063] Detergent compositions that include the protein component
have been shown to reduce fats, oils, and greases (FOG) in aqueous
solutions at levels greater than those attributable solely to the
surfactants contained in those detergent compositions. Fats, oils,
and greases are components of biological oxygen demand (BOD) and
total suspended solids (TSS), two frequently-used measures of
wastewater contaminant levels. As a result, the detergent
compositions of the present invention, including the protein
component, have the advantageous benefit of reducing BOD and TSS in
wastewater. Thus, incorporation of these detergents into aqueous
waste streams, such as institutional, commercial, industrial, or
municipal waste treatment facilities, will achieve beneficial
decreases in contaminant levels, namely, BOD and TSS. In addition,
the detergents may advantageously be used in waste transportation
lines, such as sewer lines. In such cases, effective treatment of
the waste to obtain significant decreases in FOG, BOD, and TSS may
occur while waste is being transported, and not only within the
boundaries of the waste treatment facility itself. In effect, the
transportation lines become part of the waste treatment facility
and cause treatment to occur while the waste material is being
transported to the primary facility.
[0064] All patents, patent applications, and literature references
cited in this specification are hereby incorporated by reference in
their entirety.
[0065] Thus, the compounds, systems and methods of the present
invention provide many benefits over the prior art. While the above
description contains many specificities, these should not be
construed as limitations on the scope of the invention, but rather
as an exemplification of the preferred embodiments thereof. Many
other variations are possible.
[0066] Accordingly, the scope of the present invention should be
determined not by the embodiments illustrated above, but by the
appended claims and their legal equivalents.
* * * * *